scholarly journals De novo ssRNA Aptamers against the SARS-CoV-2 Main Protease: In Silico Design and Molecular Dynamics Simulation

2021 ◽  
Vol 22 (13) ◽  
pp. 6874
Author(s):  
Francesco Morena ◽  
Chiara Argentati ◽  
Ilaria Tortorella ◽  
Carla Emiliani ◽  
Sabata Martino

Herein, we have generated ssRNA aptamers to inhibit SARS-CoV-2 Mpro, a protease necessary for the SARS-CoV-2 coronavirus replication. Because there is no aptamer 3D structure currently available in the databanks for this protein, first, we modeled an ssRNA aptamer using an entropic fragment-based strategy. We refined the initial sequence and 3D structure by using two sequential approaches, consisting of an elitist genetic algorithm and an RNA inverse process. We identified three specific aptamers against SARS-CoV-2 Mpro, called MAptapro, MAptapro-IR1, and MAptapro-IR2, with similar 3D conformations and that fall in the dimerization region of the SARS-CoV-2 Mpro necessary for the enzymatic activity. Through the molecular dynamic simulation and binding free energy calculation, the interaction between the MAptapro-IR1 aptamer and the SARS-CoV-2 Mpro enzyme resulted in the strongest and the highest stable complex; therefore, the ssRNA MAptapro-IR1 aptamer was selected as the best potential candidate for the inhibition of SARS-CoV-2 Mpro and a perspective therapeutic drug for the COVID-19 disease.

2021 ◽  
Author(s):  
Rashmi Tyagi ◽  
Anubrata Paul ◽  
V. Samuel Raj ◽  
Krishna Kumar Ojha ◽  
Manoj Kumar Yadav

<p>COVID-19 pandemic makes the human-kind standstill and results in high morbidity and mortality cases worldwide. Still, there are no approved antiviral drugs with proven efficacy nor any therapeutic vaccines to combat the disease as per the current date. In the present study, SARS-CoV-2 main protease (Mpro) has been taken as a potential drug target considering its crucial role in virus propagation. We have used 400 diverse bioactive inhibitors with proven antibacterial and antiviral properties for screening against Mpro target. Our screening result identifies ten compounds with higher binding affinity than N3 (used as a reference compound to validate the experiment). All the compounds possess desire physicochemical properties. Later on, in-depth docking and superimposition of selected complexes confirm that only three compounds (MMV1782211, MMV1782220 and MMV1578574) are actively interacting with the catalytic domain of Mpro. </p> <p>Furthermore, the selected three molecules complexed with Mpro and N3-Mpro as control are subjected to molecular dynamics simulation study (root means square deviation, root mean square fluctuation, hydrogen bonding, solvent-accessible area and radius of gyration). MMV1782211-Mpro complex shows a strong and stable interaction as compared to others. The MM/PBSA free energy calculation shows the highest binding free energy of –115.8 kJ/mol for MMV1782211 compound also cross-confirms our molecular docking study. Therefore, our <i>in silico</i> findings become very interesting towards developing alternative medicine against SARS-CoV-2 Mpro target. So, we can expect prompt actions in this direction to combat the COVID-19.</p>


Author(s):  
Adi Tiara Zikri ◽  
Harno Dwi Pranowo ◽  
Winarto Haryadi

Stability and hydrogen bond occupancy analysis of flavonol derivative docked in DAPK1 have been carried out using molecular dynamics simulation approach. Six flavonol derivatives were docked in DAPK1 as protein target, then continued with molecular dynamics simulation. NVT and NPT ensembles were used to equilibrate the system, followed by 20 ns sampling time for each system. Structural stability and hydrogen bond occupancy analyses were carried out at the NVT ensemble, while free binding energy analysis was done at NPT ensemble. From all compounds used in this work, compound B (5,7-dihydroxy-2-(4-hydroxyphenyl)-6-methoxy-4H-chromen-4-one) has a similar interaction with reference ligands (quercetin, kaempferol, and fisetin), and the most stable complex system has the maximum RMSD around 2 Å. Compound C complex has -48.06 kJ/mol binding free energy score, and it was slightly different from quercetin, kaempferol, and fisetin complexes. Even though complex C has similar binding free energy with the reference compound, complex B shows more stable interactions due to their hydrogen bond and occupancy.


2021 ◽  
Author(s):  
Rashmi Tyagi ◽  
Anubrata Paul ◽  
V. Samuel Raj ◽  
Krishna Kumar Ojha ◽  
Manoj Kumar Yadav

<p>COVID-19 pandemic makes the human-kind standstill and results in high morbidity and mortality cases worldwide. Still, there are no approved antiviral drugs with proven efficacy nor any therapeutic vaccines to combat the disease as per the current date. In the present study, SARS-CoV-2 main protease (Mpro) has been taken as a potential drug target considering its crucial role in virus propagation. We have used 400 diverse bioactive inhibitors with proven antibacterial and antiviral properties for screening against Mpro target. Our screening result identifies ten compounds with higher binding affinity than N3 (used as a reference compound to validate the experiment). All the compounds possess desire physicochemical properties. Later on, in-depth docking and superimposition of selected complexes confirm that only three compounds (MMV1782211, MMV1782220 and MMV1578574) are actively interacting with the catalytic domain of Mpro. </p> <p>Furthermore, the selected three molecules complexed with Mpro and N3-Mpro as control are subjected to molecular dynamics simulation study (root means square deviation, root mean square fluctuation, hydrogen bonding, solvent-accessible area and radius of gyration). MMV1782211-Mpro complex shows a strong and stable interaction as compared to others. The MM/PBSA free energy calculation shows the highest binding free energy of –115.8 kJ/mol for MMV1782211 compound also cross-confirms our molecular docking study. Therefore, our <i>in silico</i> findings become very interesting towards developing alternative medicine against SARS-CoV-2 Mpro target. So, we can expect prompt actions in this direction to combat the COVID-19.</p>


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1004
Author(s):  
Mahmoud A. El Hassab ◽  
Mohamed Fares ◽  
Mohammed K. Abdel-Hamid Amin ◽  
Sara T. Al-Rashood ◽  
Amal Alharbi ◽  
...  

Since December 2019, the world has been facing the outbreak of the SARS-CoV-2 pandemic that has infected more than 149 million and killed 3.1 million people by 27 April 2021, according to WHO statistics. Safety measures and precautions taken by many countries seem insufficient, especially with no specific approved drugs against the virus. This has created an urgent need to fast track the development of new medication against the virus in order to alleviate the problem and meet public expectations. The SARS-CoV-2 3CL main protease (Mpro) is one of the most attractive targets in the virus life cycle, which is responsible for the processing of the viral polyprotein and is a key for the ribosomal translation of the SARS-CoV-2 genome. In this work, we targeted this enzyme through a structure-based drug design (SBDD) protocol, which aimed at the design of a new potential inhibitor for Mpro. The protocol involves three major steps: fragment-based drug design (FBDD), covalent docking and molecular dynamics (MD) simulation with the calculation of the designed molecule binding free energy at a high level of theory. The FBDD step identified five molecular fragments, which were linked via a suitable carbon linker, to construct our designed compound RMH148. The mode of binding and initial interactions between RMH148 and the enzyme active site was established in the second step of our protocol via covalent docking. The final step involved the use of MD simulations to test for the stability of the docked RMH148 into the Mpro active site and included precise calculations for potential interactions with active site residues and binding free energies. The results introduced RMH148 as a potential inhibitor for the SARS-CoV-2 Mpro enzyme, which was able to achieve various interactions with the enzyme and forms a highly stable complex at the active site even better than the co-crystalized reference.


2021 ◽  
Vol 14 (6) ◽  
pp. 541
Author(s):  
Hani A. Alhadrami ◽  
Ahmed M. Sayed ◽  
Heba Al-Khatabi ◽  
Nabil A. Alhakamy ◽  
Mostafa E. Rateb

The COVID-19 pandemic is still active around the globe despite the newly introduced vaccines. Hence, finding effective medications or repurposing available ones could offer great help during this serious situation. During our anti-COVID-19 investigation of microbial natural products (MNPs), we came across α-rubromycin, an antibiotic derived from Streptomyces collinus ATCC19743, which was able to suppress the catalytic activity (IC50 = 5.4 µM and Ki = 3.22 µM) of one of the viral key enzymes (i.e., MPro). However, it showed high cytotoxicity toward normal human fibroblasts (CC50 = 16.7 µM). To reduce the cytotoxicity of this microbial metabolite, we utilized a number of in silico tools (ensemble docking, molecular dynamics simulation, binding free energy calculation) to propose a novel scaffold having the main pharmacophoric features to inhibit MPro with better drug-like properties and reduced/minimal toxicity. Nevertheless, reaching this novel scaffold synthetically is a time-consuming process, particularly at this critical time. Instead, this scaffold was used as a template to explore similar molecules among the FDA-approved medications that share its main pharmacophoric features with the aid of pharmacophore-based virtual screening software. As a result, cromoglicic acid (aka cromolyn) was found to be the best hit, which, upon in vitro MPro testing, was 4.5 times more potent (IC50 = 1.1 µM and Ki = 0.68 µM) than α-rubromycin, with minimal cytotoxicity toward normal human fibroblasts (CC50 > 100 µM). This report highlights the potential of MNPs in providing unprecedented scaffolds with a wide range of therapeutic efficacy. It also revealed the importance of cheminformatics tools in speeding up the drug discovery process, which is extremely important in such a critical situation.


2019 ◽  
Vol 19 (2) ◽  
pp. 461
Author(s):  
Herlina Rasyid ◽  
Bambang Purwono ◽  
Thomas S Hofer ◽  
Harno Dwi Pranowo

Lung cancer was a second common cancer case due to the high cigarette smoking activity both in men and women. One of protein receptor which plays an important role in the growth of the tumor is Epidermal Growth Factor Receptor (EGFR). EGFR protein is the most frequent protein mutation in cancer and promising target to inhibit the cancer growth. In this work, the stability of the hydrogen bond as the main interaction in the inhibition mechanism of cancer will be evaluated using molecular dynamics simulation. There were two compounds (A1 and A2) as new potential inhibitors that were complexed against the EGFR protein. The dynamic properties of each complexed were compared with respect to erlotinib against EGFR. The result revealed that both compounds had an interaction in the main catalytic area of protein receptor which is at methionine residue. Inhibitor A1 showed additional interactions during simulation time but the interactions tend to be weak. Inhibitor A2 displayed a more stable interaction. Following dynamics simulation, binding free energy calculation was performed by two scoring techniques MM/GB(PB)SA method and gave a good correlation with the stability of the complex. Furthermore, potential inhibitor A2 had a lower binding free energy as a direct consequence of the stability of hydrogen bond interaction.


2019 ◽  
Author(s):  
Anam Arooj ◽  
Muhammad Tariq Pervez ◽  
Zeeshan Gillani ◽  
Tahir Ali Chohan ◽  
M. Tayyab Chaudhry ◽  
...  

AbstractCYP11B2gene is located over the upper layer of the kidney. It produces aldosterone synthase enzyme and thereby has an essential role to balance salt and mineral level in the body. A mutation in this gene can deregulate the production of aldosterone hormone in the body which may lead to many diseases including hypertension and cardiac diseases. To control the excess production of this aldosterone an inhibitor “Fadrozole” is being used which is associated with an active site cavity of CYP11B2. This study has been divided into two parts. In the first part, the four computational tools (SIFT, Polyphen-2, I-Mutant, ConSurf) were used to identify 29 deleterious SNPs out of 1600CYP11B2SNPs. In the second part, five residues (R448G, R141P, W260R, F130S, and F445S) were identified in the active site cavity (out of 29 deleterious CYP11B2 SNPs) at the distance of 5A°. Binding free energy calculation as well as Dynamics simulation techniques were applied to determine the effect of these mutations on the CYP11B2-Fadrozole compound. The results showed thatFadrozolebinding with CYP11B2 became stronger which proved the efficiency of this drug inhibitor with these highly damaging mutations. Our study will be useful for selecting the high priority CYP11B2 mutations, which could be further, investigated in this gene-associated study, for better understanding of the structural and functional aspects of the observed (CYP11B2) protein.


2020 ◽  
Author(s):  
Rakesh Kumar ◽  
Rahul Kumar ◽  
Pranay Tanwar

Abstract SARS-CoV2, a new coronavirus has emerged in Wuhan city of China, December last year causing pneumonia named COVID-19 which has now spread to entire world. By April 2020, number of confirmed cumulative cases crossed ~2.4 million worldwide, according to WHO. Till date, no effective treatment or drug is available for this virus. Availability of X-ray structures of SARS-CoV2 main protease (Mpro) provided the potential opportunity for structure based drug designing. Here, we have made an attempt to do computational drug design by targeting main protease of SARS-CoV2. Highthroughput virtual screening of million molecules and natural compounds databases was performed followed by docking. Six ligands showed better binding affinities which were further optimized by MD simulation and rescoring of binding energy was calculated through MM/PBSA method. In addition, conformational effect of various ligands on protein was examined through essential dynamics simulation. Three compounds namely ZINC14732869, ZINC19774413 and ZINC19774479 were finally filtered that displayed high binding free energies than N3 inhibitor and form conformationally stable complex. Hence, current study features the discovery of novel inhibitors for main protease of CoV2 which will provide effective therapeutic candidates against COVID19.


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